Mandrel assembly



Jam 9 1940 v P. R. ARoNsoN 2,186,088

MANDREL AS SEMBLY Filedvnec. 51, 1958 'L 5. INVEINTOR J4 E PETER R. ARoNsoN BY I ATTORNEY Patented Jan. 9, 1940 Peter It. Aronson, Millburn, N. J., assigner to rOxweld Acetylene Company, a corporation of v `West' Virginia Application December s1, 193s, serial No. 248.725

12 claims. (ci. 'is-.103) i 'l ,Ifhis invention relates to the art of metal Working and particularly to a mandrel assembly for l use With ductile metal blanks having rough,

, oversize passages therethrough, and which are the form of the completed nozzle.

adaptedl to be subjected to metal-'Working operations to form blowpipe nozzles and the like. l 4One process of makingfblowpipe nozzles com-y prises swaging blanks yof copper bar-stock into The blanks are provided with longitudinally rdrilled rough, oversize-passages including v a `central oxygen passage 'and a series of'preheat passages, in all of which passages, mandrels in the form of rnusicnwire are inserted. One such method is disclosed in United States patent application Serial No. 158,703 filed August 12.1937, by P. R. Aronson. By virtue of the swaging operation, the length of thev metal blank is increased, and

its 'cross-sectional area as wellas that of the rough oversize 4passages is reduced,the.latter rconforming with the cross-section of the Wire mandrels.

`Blowpipe nozzles have also .been produced by pressure-forming metal blanks of the above-described type having wire mandrels Within the oxygen and preheat passages thereof. This `latter method comprises the continued forcing of a blank mounted on a mandrel assembly into :,v a die having substantially the formof the finished 30r nozzle.' One form of making blowpipe nozzles inaccordance with this latter method is disclosed in United States patent application Serial No. 168.1414 filed October 9, 1937, by'Chalmers K.

lBryce et al.

upon the mandrel wires with a minimum of effort and time; and if the lmandrels can be extracted withoutv injury from the swaged or pressureformed nozzle.

v mandrel assembly of simple construction and v capable'of overcoming the above andother diili-` ,L mandrel assembly. with means for. facilitating the culties. Other objects include, the provision of a mounting of vmetal blanks thereon; the-provision of such a mandrel assembly in which. the

- `Inandrels are designed and constructed so that provision of a combined mandrel assembly and 55 they can be repeatedly used Without failing; the

punch for supporting a vmetal blank during a An object of this invention .isV to provide a pressure-formingoperation; and the provision of a combined mandrel assembly and punch capaable of interchangeably supporting in accurate relation a` plurality of Wire mandrels ofv different' effective size.

The above and other objects and novel features of this invention will become apparent from the following specification considered in connection with the accompanying drawing in which:

Fig. l is an'end elevational view of a mandrel 'assembly constructed in accordance with the principles of this invention;

Fig. Zis a top plan view, partly in section, of

the assembly shown in Fig. 1;

Fig. 3 is a sectional vevvv taken along line 3 3 of Fig. 1;

Fig. 4 is an end elevational view of a modified form of mandrel assembly `constructed in accordance with this invention;

Fig. 5 is a sectionalv view takenA 5`5 of Fig. 4; l p

Fig.V 6 is an end elevational view looking at the along line right-hand end of the assembly shown in Fig. 5;

` Fig. '7 is an end elevational view of another modied form of mandrel assembly constructed in accordance with this invention; and

Fig. 8 is a sectional elevational view' taken along line 8--8 of Fig. '7. y Referring to Figs. 1, 2 and/3, a head I0 of bronze or other ductilemetal is provided with accuratelyvspaced passagesextending longitudinally therethrough for receiving a series of mandrel WiresIZ which may be formed, from music Wire or heat-treatedjdrill-rod stock. "Ihe numberl and arrangement of the passages Within `the head I0 correspond with the number of preheat passages as Well as the central oxygen passage Within a ductile metal blank` II to be subjected tota swaging or pressure-forming operation. Cer- .tain of the mandrels I2 are cut in lengths sufricient to be formed into U-shaped elements, each leg of Which constitutes "a mandrel for a passage Within the metal blank-I I. The head vIl) is further provided vvith'a recessed end portion I4, and in the embodiment shown, jtwo U-shaped elef ments are mounted in the head I0 so that the legs of each extend beyond the one end thereof.

The portion of each U-shaped element,` which connects the respective legs. I2, seats within the recess I4 in a manner so that it does not extend beyond the end of` head Ill in which said recess I4 is located. p

vReferring to Fig. 3, one of the mandrels I2, adapted to fit within. thecentral or oxygen passage of the blank' II, is positioned Withinv a central passage I3 within head I0. The oxygen passage mandrel I2 is of the same wire that the other mandrels are, and itis bent into a genera] U-shaped element with one leg I substantially shorter than the other. This short-legged U- shaped element is fed into a pair of the passages including the passage I3 within head I, and the short leg I5 is bent at right angles to the other leg and fits along the end of the head lll opposite to that in which recess Ill is located.

The head Iii, with its assembly of mandrels, is then fed (head first) into a swaging machine to effect a rigid grip `between the head and each of the wire mandrels, and/or the recess Ill may be filled with solder.

For the purpose of facilitating the mounting of the blank i I on the mandrel wires I2, a spacer or spreader E6 is provided. `It comprises a cylindrical piece of aluminum drilled with holes equal in number and corresponding in locationto the passages within the blank II and the head it. The size ofthe holes in the aluminum spreader are such that it freely slides over the mandrel wires I2. By positioning the spreader I5 near the free end of the mandrel Wires 5 2, the latter may be readily inserted into the passages within blank II.

The embodiment of the invention disclosed in Figs. l, 2 and 3, illustrates an arrangement whereby five inandrels are employed. It is to be understood that any number and arrangement of mandrels may be employed in constructing an assembly in accordance with the teachings of the invention. I

When it is desired to produce a swaged or pressure-formed blowpipe nozzle of the type employing a low-pressure, high-volume oxygen stream, a different form of mandrel assembly is necessary in order to provide a suiciently large central oxygen passage within the nozzle blank capable of accommodating a low-pressure largevolume oxygen jet. Referring to Figs, Ll, 5 and 6, a modied form of mandrel assembly isy disclosed in which a head IS is substantially identical with the head Il of Fig. 2 in that it is adapted to support a series of mandrel wires 20 identical with, and in the same manner as the wires I 2 of Fig. 2 are supported. The Wires 2li serve in the present instance as mandrels for the preheatpassages Within a metal blank 22. The head I3 is provided with a relatively large central passage 2d adapted to receive a mandrel 26 the cross-section of which is substantially greater than that of the wire mandrels 3. The mandrel 2G is provided with a head 23 adapted to seat within the recess of head l8r; a shank portion 25 of constant cross-section adapted to accurately fit within passage 2li; and a tapered portion 21 adapted to iit within the relatively large central oxygen passage of the blank 22. Because of its tapered construction, the mandrel 2S is easily withdrawn from the blank 22 after the swaging operation. A spreader or spacer 2S, similar to the spacer I3 of Fig. 2, is adapted to slidingly lit the mandrel wires 2G. It is provided with a suilciently enlarged central passage 29 to enable its movement longitudinally of the wires 23 without interfering with the tapered mandrel 26.

When it is desired to produce a blowpipe nozzle in accordance with the pressure-forming method referred to, a still further modified form of mandrel assembly is employed. Referring to Figs. 'l and 8, a head 30, which functions as a comb-ined punch and mandrel support, is provided withfan elongated portion 32 ground peripherally to pro- Vide an accurate sliding t with a guide portion of a die Within which the metal blank is adapted to be forced. The head 30 is also provided with a portion 34 constructed in a manner to facilitate its engagement with the gripping element of a power press. The portion 34 comprises a relatively thick flange integral with the elongated body portion 32, and it is arranged to be received by the gripping element of the press.

Mandrels 36, equal in number to the passages within a metal blank 31 to be formed, are removably held in the head 30 in positions corresponding to the relative' locations ofthe passages Withinthe metal blank 31. The design and construction of the mandrels 36 are such as to lessen the frictional force set up between them and the coldrlowing metal of blank 31 during the pressureforming operation. They may be constructed of cold-drawn Wire, and provided with a shank portion, equal in length to the overall length of the head 3E. vTheforward portion of each mandrel 36 is preferably tapered in the direction of thev now of metal during the pressure-forming operation. The tapered construction of the mandrels, together with the fact that they are made from cold-drawn wire, lessens the frictional force set up between the cold-flowing metal and the mandrels. This is apparently due, at least in part, to the longitudinal arrangement of the grain structure of the cold-drawn wire from which they are made. A bronze knob 38 is welded or swaged to the shank end of eachmandrel 36. The Welding of the bronze knob to the steel mandrel wire does not affect the hardness and exibility of the wire because the temperature necessary to effect a bronze weld is Well below that temperature which would cause a metallurgical change in the steel wire. When it is desired to swage the knob 38 onto the shank .end of a mandrel 36, the latter is roughened or knurled in order to insure a good grip between the knob and mandrel.

The mandrel wires 36 are adapted to be positioned within accurately arranged passages 39 withinv the head 3U. The passages 39 correspond with the number and location of the passages within the metal blank 31. The bronze knob 38 of each mandrel 36 is adapted to be received Within a counterbore 4| formed within the face of the ilanged end 34 of head 30. The head 30 may be employed with mandrels having effective portions of diferent size since the cross-section of the mandrel shank portions as Well as that of the knobs 38 may be the same for mandrels of different effective size.

A sliding spacer element 40 having passages 43 equal in number to, and located in corresponding positions with, the passages within blank 31, is slidingly positioned on the mandrel wires 36. It facilitates the assembly of the metal blank 31 onto the mandrels 36 in the same manner as the spacers I6 and 28 function.

Althoughv the various features of the mandrel assembly have been shown and described inv detail to fully disclose several embodiments ofthis invention, it will be evident that numerous changes may bemade in details and certain features may be used without others, without departing from.

the principles of the invention.

What is claimed is: l. A mandrel assembly for use with ar metal blank having a plurality of passages therethrough r.spaced relation; and spacer means mounted .on

equal in number to,v and located in accordance with passages within said metal blank.

4. A mandrel'assembly as claimed in claim 1,

` in which said wire mandrels include atleast one U-shaped wire, and said head is provided with a recessed end'adapted to receive the portion of said rU-shaped wire that joins the respective legs thereof, whereby said portion does not protrude beyond the end of said head which is recessed. y

5. A mandrel assembly as claimed in claim 1, in which the means mounted on the wire mandrels for facilitating mounting a blank thereon comprises a spacer having a series of passages equal in number, and spaced in accordance with the location of the passages within` said blank, and in which said spacer is adapted to slidingly engage said wire mandrels.

6. A mandrel assembly as claimed in claim 1,v in which said head and spacer means are each g in which said head is provided with a series of provided with an aligned central passage adapted to receive and position a central mandrel of `substantially greater diameter than said wire mandrels. f

7. A mandrel assembly as claimed in claim 1, in which said head and spacer means are each which a tapered mandrel, having a greater diameter than said wire mandrels is positioned Within said central passages, the size of the cenportion and a press-gripping portion.

V9. A mandrel assembly las claimed in claim 1, in which'said head comprises an elongated shank portion and a press-gripping portion, and in which said portions are provided with a series of passages adapted rto interchangeably receive wire` `provided with an aligned central passage; and

mandrels having effective portions 4of different f sizeand adapted to position the'same in predetermined spaced relation.

1,0. A mandrel assembly as claimed in claim 1,l

in ywhich said wire mandrels are provided with 'means cooperating with said head so that they may be removed'from said head only by movement in one direction.

11.' `A mandrel assembly as claimed in claim 1, in which each ofy said mandrels is provided at one end with a bronze knob ate with saidhead.

12, A mandrelassemblyas claimed in claim 1,

elongated passages counterbored atone end for receivingfknobs connected to the one end of each f mandrel wire, whereby said knobs do not proadapted to cooper- 

